Proper bolt contact?

[Hatrick]

I have a Rem 700 that was recently re-barreled, along with truing up the old action. I do a good job of lubing the back of the lugs where they contact the action, but I noticed that other day that there seems to be some light contact to the front of the lug as well.

I know on my Savage there is probably at least .010" space between the barrel and the front of the bolt head when locked, but the floating bolt head is a different set up than a Remmy.

Do you guys think it is an issue with the Remington, or is the front of the lug supposed to contact that collar around the chamber?

 

[Eddie Harren]

NO!

 

[spclark]

I think you need to re-visit your gunsmith, have him take a cut off the breech end of that new barrel. If your bolt's lugs are contacting it, you'll be chasing your tail trying to get it to shoot accurately. The barrel ought to touch the action ONLY at the designed surface, not touch the bolt AT ALL.

 

[Hatrick]

I think you need to re-visit your gunsmith, have him take a cut off the breech end of that new barrel. If your bolt's lugs are contacting it, you'll be chasing your tail trying to get it to shoot accurately. The barrel ought to touch the action ONLY at the designed surface, not touch the bolt AT ALL.

Yep, I have already been chasing my tail trying to find a load that will shoot consistent with this thing. I just disassembled the rifle to get the stock ready for bedding, and was trying to make sure that nothing else jumped out at me that may effect accuracy.

Would it be okay to mill a small amount of material off the front of the bolt lugs, or does the barrel have to come back out of the action?

 

[RickB]

Don't do that. It will make your action different than what it should be when the next barrel needs to be fitted and will unnecessarily remove material from the bolt. Have him pull the barrel and properly fit it to the action.

 

[spclark]

Would it be okay to mill a small amount of material off the front of the bolt lugs, or does the barrel have to come back out of the action?

You paid good money to have a proper job done. You now have reason to believe the job was NOT done properly.

Unless it's been months since you picked the rifle up / received it back after being shipped, you have every right to request of your gunsmith that he spend the time necessary to make good.

It shouldn't be a big deal to take a skim cut off the breech end of the barrel once it's out of the action. It shouldn't affect head spacing if that was done right. (WAS the new barrel properly checked for correct head space??)

Reconfiguring the face of your bolt lugs is something that will be with that part forever once done. Trying to correct a mistake with another is generally not considered to be good practice... save for maybe in Washington D.C.

There's no good reason to modify the bolt to make up for a mistake in fitting a barrel, but many good reasons to have a mis-fitted barrel corrected.

 

[gunsandgunsmithing]

Remove the firing pin assembly and put the stripped bolt in the gun. Close the bolt on an empty chamber. Try pushing and pulling the bolt straight forward and back. Is there ANY movement? If so, this is your clearance. You can check it with a dial indicator or even feeler gauges. The bolt should NOT touch the barrel with a piece of brass in the chamber, but should on an empty chamber unless the bolt handle is timed to less clearance than the bolt to barrel clearance. Think about it like this...without the bolt handle and cocking piece, what would stop the bolt from falling out the front of the action, with no barrel.--Mike Ezell

 

[Hatrick]

Remove the firing pin assembly and put the stripped bolt in the gun. Close the bolt on an empty chamber. Try pushing and pulling the bolt straight forward and back. Is there ANY movement? If so, this is your clearance. You can check it with a dial indicator or even feeler gauges. The bolt should NOT touch the barrel with a piece of brass in the chamber, but should on an empty chamber unless the bolt handle is timed to less clearance than the bolt to barrel clearance. Think about it like this...without the bolt handle and cocking piece, what would stop the bolt from falling out the front of the action, with no barrel.--Mike Ezell

Thanks for the advice.

Okay, I stripped the bolt, blackened the front of the lugs, and opened and closed it on a new empty case, and from what I can tell the front of the lug never made contact with the barrel...which is good.

Using a set of feeler gauges, I measured the slop, or what would be the clearance at only .006".
Is .006" enough clearance, even for a target rifle?

There are some machining marks on the back of my lugs, and one lug does not show wear over the entire surface. Would it be some help to lap these lugs for better contact, maybe even moving the bolt head back a thou or two? My chamber is plenty tight on a new case or a go gauge, in case that would be an issue.

 

[Kings X]

.006" is about right.
The lugs can be lapped now. It should have been done before headspacing. But if is tight - lapping will be fine to do now.
The front of the lug and the front of the bolt face should clear the barrel. If either one just kisses the back of the barrel - they can be filed until they clear. Clearance is clearance. The small amount of material removed can't be more than .002". Because .002" error and the bolt will not close on an empty chamber.
The uneven lugs will have a small effect on accuracy. What you would see is two groups with full length sized cases.
Richard King